I think I have 220v service from my electric company and at the meter the circuit box is converting it to 110. How do I tell if this is true?

Try this How to Use an Ohm Meter to Test 220 Volts | eHow.com (http://www.ehow.com/how_7568415_use-meter-test-220-volts.html)

A typical home in USA and Canada has a 120 and 240 volt service.

The meter does nothing but measure watts used and time.

99.99% chance you have 120/240v like everyone else. There is no "conversion" done anywhere.
The fact that there is a neutral present in the service is where you get the 120v from.

Why do you ask?

The reason I ask is I want to install a Jacuzzi on my roof... The manual for the Jacuzzi calls for 4 wire 220 and from what I have read it is best to have it's own line from the source with it's own junction box.

Sorry I should have mentioned I am in Mexico

Thanks for the link on hnow to use an ohm meter...

There's WAY more to it than that.

"220" is only part of it.

What do you mean stanfortyman

"There's WAY more to it than that.

"220" is only part of it."??

I already bought 40 meters of red and 40 meters of black 6 gauge wire.

Is this something I can do or do I need to hire an electrician?

Just curious, but is the structure of the roof strong enough to hold the weight of a tub full of water, plus the weight of the people in the tub?

Are there overhead service cables above any part of the tub?

As to the electrical needs:

Your hot tub installation must conform to Article 680, Part IV of the NEC if adopted by Mexico.

Also, because this is an outside installation, you also have to conform to Article 680, Parts I and II.

There are height restrictions for devices like fans and lights and these are further subdivided by whether you are installing them with GFCI circuits or not.

Next, you have to conform to the installation requirement for panelboards and feeders.

If you are not familiar with the work needed, you would be wise to seek the services of a licensed electrician.

The electrical code is about safety and you do not want to make an error around any installation where there is water.

The building is built of steel I beams and cement and the engineers advised me that the location where I placed the Jacuzzi is perfect in relation to the I beams for maximum support.

I have no obligation to get any permits or inspections on the installation of the electrical wiring but do want to be safe.

The owner's manual says keep any electrical appliances or lighting at least 5 feet from the Jacuzzi and I am definitely going to comply.

And last but not least electricians in Mexico are not required to have licenses to offer their services. So getting anyone who says they are an electrician or me learning what I need to learn and taking my time to make sure I am doing the right thing is a safer bet (in my opinion)

I have already paid a crane to place the jacuzzi on the roof and filled it with water... it has been up there for several days. Obviously there is going to be considerable more weight when we add the humans to the jacuzzi but several of us have hung out on the deck I have made for the Jacuzzi and no sign of any weight issues yet...

I already bought 40 meters of red and 40 meters of black 6 gauge wire.
How do you know you need #6?
What about the ground?
Does the tub require a neutral?
What size service do you have?

I know it is 6 gauge because there is a placard on the side of the jacuzzi declaring 6 gauge is required

Now I have received an owner's manual for the jacuzzi and it also says 6 gauge is required.

My original question is how do I tell whether I have 110 or 220 or both... (is that what you mean by size service?)

My original question is how do I tell whether I have 110 or 220 or both... (is that what you mean by size service?)No, it is not.

I firmly believe that anyone who doesn't know the difference between amperage and voltage, and cannot tell the difference between a 120v service and a typical 120/240v service, has NO place wiring something as critical as a hot tub.

I am bowing out of this thread.

I am not wiring my own hot tub... I am learning what is going on in my house while I am paying an electrician to wire my hot tub.

I appreciate your advice and the information you have provided so far. I am sorry you decided to not continue.

You would use a tester to test the voltage where the power comes in from the pole to the house ( some type of breaker or circuit box) and /or the main shut off to the house.

But I agree, have the electrician show you how to test, where the main is, and so on.

If all you want to do is learn, then go to a big box store, like "Lowes" or "Home Depot" or even a book store like "Barnes and Noble".

There are numerous books on wiring one of my favorites is by Ray C Mullin, "Residential Wiring".

The 16th edition covers the 2008 NEC and the 17th edition covers the 2011 NEC.

The cause for concern is safety. Electricity can injure or kill. You have to have some knowledge about what you are doing before you start in using using a meter or tools.

The term "Service Size" actually refers to the amount of amperage you are getting from the utility company.

For us here in the U.S.A. our minimum service must be 100 Amps. Higher levels of amperage are available from the utility company such as 125 amp, 150 amp and 200 amp.

One safe way to find out what type of service you have is to take a look at the appliances you have in your home.

If you have a 240 Volt electrical clothes dryer it will say so on the metal tag on the dryer. It will also tell you the number of Amps needed for this appliance.

The same is true for smaller appliances. So you can check your kitchen appliances for the same type tag. If you see appliances with a 120/240 voltage,
You more than likely have both 120 / 240 VAC.

You can also just call your utility company and ask them what voltages you have.